Well, I’m getting pretty good mileage out of this book! OK, here’s a nugget that I’m likely to forget if I don’t write it down : When scientists measured the average speed of runners in the New York Marathon, they discovered that times improved from 19 years old through to a peak at 27. So far so good. What’s surprising is that it’s not until 64 years old that performance drops back to the same as it was at 19.